The human blood platelet as a model for studying interactions of ethanol with membrane lipids.

The effect of ethanol on human blood platelet aggregation is generally inhibitory, but aggregation caused by arachidonic acid is either unaffected or potentiated by ethanol. Of the other aggregatory agents tested, the calcium ionophore A23187, collagen, and thrombin were most inhibited by ethanol. These results suggest that in the case of collagen and ionophore A23187 ethanol may act to inhibit aggregation at some point between the rise in cytosolic calcium and the cleavage of membrane phospholipids associated with the platelet release reaction. A similar spectrum of inhibition was produced by the incorporation of unsaturated fats into the platelet or by reduction of divalent cations by addition of EDTA to the external medium. Platelets in which unsaturated fats were incorporated were less susceptible to inhibition by ethanol than those into which saturated fats had been incorporated.